Helleborus plant named ‘COSEH 740’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 740’, characterized by its upright and outwardly arching plant habit; uniform flowering habit; dark green-colored leaves; long flowering period; numerous single white-colored flowers; and good garden performance.

Botanical designation: Helleborus×ericsmithii.

Cultivar denomination: ‘COSEH 740’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Helleborus plant, botanically known as Helleborus×ericsmithii, and hereinafter referred to by the name ‘COSEH 740’.

The new Helleborus plant is a product of a planned breeding program in Glandorf, Germany. The objective of the breeding program was to create new uniform Helleborus cultivars with unique and attractive flower coloration and resistance to pests.

The new Helleborus plant originated from a cross-pollination conducted by the Inventor in Glandorf, Germany in November, 2002 of two unnamed proprietary seedling selections of Helleborus×ericsmithii, not patented. The new Helleborus plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination grown in a controlled greenhouse environment in Glandorf, Germany in February, 2005.

Asexual reproduction of the new Helleborus plant by divisions in a controlled greenhouse environment in Glandorf, Germany since March, 2005, has shown that the unique features of this new Helleborus plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment and cultural practices such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘COSEH 740’. These characteristics in combination distinguish ‘COSEH 740’ as a new and distinct cultivar of Helleborus plant:

-   -   1. Upright and outwardly arching plant habit.     -   2. Uniform flowering habit.     -   3. Dark green-colored leaves.     -   4. Long flowering period.     -   5. Numerous single white-colored flowers.     -   6. Good garden performance.

Compared to plants of the parent selections, plants of the new Helleborus flower more freely and more uniformly.

Plants of the new Helleborus can be compared to plants of Helleborus niger×Helleborus lividus ‘COSEH 710’, disclosed in U.S. Plant patent application Ser. No. 12/319,424. Plants of the new Helleborus differ primarily from plants of ‘COSEH 710’ in the following characteristics:

-   -   1. Plants of the new Helleborus are not as vigorous as plants of         ‘COSEH 710’.     -   2. Flowers of plants of the new Helleborus are white in color         whereas flowers of plants of ‘COSEH 710’ are light green in         color with reddish pink overtones.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearance of the new Helleborus plant, showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Helleborus plant.

The photograph on the first sheet comprises a side perspective view of a typical flowering plant of ‘COSEH 740’ grown in a container.

The photograph on the second sheet is a close-up view of a typical flower of ‘COSEH 740’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurements and values describe plants grown in Glandorf, Germany in 1.5-liter containers during the winter in a glass-covered greenhouse and under conditions which closely approximate commercial Helleborus production. During the production of the plants, day temperatures ranged from 12° C. to 32° C. and night temperatures ranged from 3° C. to 18° C. Plants were one year old when the photographs and the description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2007 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus×ericsmithii ‘COSEH 740’. -   Parentage:     -   -   Female, or seed, parent.—Unnamed proprietary seedling             selection of Helleborus×ericsmithii, not patented.         -   Male, or pollen, parent.—Unnamed proprietary seedling             selection of Helleborus×ericsmithii, not patented. -   Propagation:     -   -   Type.—By tissue culture.         -   Time to initiate roots.—About two months at 12° C.         -   Time to produce a rooted young plant.—About six months at             4° C. to 15° C.         -   Root description.—Thick to thin, fleshy; white to brown in             color.         -   Rooting habit.—Sparse. -   Plant description:     -   -   Plant form and growth habit.—Herbaceous perennial; upright             and outwardly arching plant habit with flowers held above             the foliar plane; shape, globular; moderately vigorous             growth habit.         -   Plant height.—About 26 cm.         -   Plant diameter (area of spread).—About 43.7 cm. -   Foliage description:     -   -   Arrangement.—Leaves arranged in a basal rosette; palmately             compound with five leaflets per leaf.         -   Leaf length.—About 18.2 cm.         -   Leaf width.—About 22.4 cm.         -   Leaflet length.—About 13.9 cm.         -   Leaflet width.—About 4.6 cm.         -   Leaf shape.—Palmate; orbicular in outline.         -   Leaflet shape.—Elliptic to ovate.         -   Leaflet apex.—Acute.         -   Leaflet base.—Attenuate.         -   Leaflet margin.—Sharply serrate.         -   Leaflet texture, upper and lower surfaces.—Smooth, glabrous;             leathery.         -   Leaflet venation pattern.—Pinnate.         -   Leaflet color.—Developing leaves, upper surface: Between             N137D and 147A; base tinged with close to N186C. Developing             leaves, lower surface: Close to 147B; base tinged with close             to N186C. Fully developed leaves, upper surface: Close to             147A; venation, darker than between 147A and N189A. Fully             developed leaves, lower surface: Close to 147B; venation,             close to 147B.         -   Petiole.—Length: About 9.8 cm. Diameter: About 7 mm.             Texture, upper and lower surfaces: Smooth, glabrous. Color,             upper and lower surfaces: Close to 144A with spots, close to             177A. -   Flower description:     -   -   Flower shape and habit.—Single rotate flowers; uniform             flowering habit; about seven flowers per terminal cyme;             flowers facing slightly outwardly to nodding.         -   Fragrance.—None detected.         -   Natural flowering season.—Long flowering period; plants             flower from winter to early spring in Germany.         -   Flower longevity on the plant.—About ten days; flowers not             persistent.         -   Flower buds.—Length: About 1.4 cm. Diameter: About 1 cm.             Shape: Obovate. Color: Close to 144D flushed with close to             174B.         -   Inflorescence height.—About 26 cm.         -   Inflorescence diameter.—About 19.6 cm.         -   Flower diameter.—About 6.5 cm.         -   Flower depth (height).—About 2.6 cm.         -   Petals.—Transformed into nectaries.         -   Sepals.—Arrangement: About five in a single whorl. Length:             About 3.3 cm. Width: About 2.4 cm. Shape: Broadly elliptic             to broadly obovate. Apex: Rounded to emarginate. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color: When opening, upper surface: Close to 145C to 145D to             157A; towards the base, close to 145B. When opening, lower             surface: Close to 145C to 145D to 157A; center flushed with             close to 174C to 174D; towards the base, close to 145B.             Fully opened, upper surface: Close to 145D to 157A to 157B;             towards the base, close to 145B to 145C; color becoming             closer to 144B with development. Fully opened, lower             surface: Close to 145D to 157A to 157B; towards the base,             close to 145C.         -   Peduncles.—Strength: Moderately strong. Length: About             16.7 cm. Diameter: About 1 cm. Aspect: About 10° from             vertical. Texture: Smooth, glabrous. Color: Close to 145C             with spots, close to 182B.         -   Pedicels.—Strength: Moderately strong. Length: About 3.6 cm.             Diameter: About 3 mm. Aspect: About 30° from the peduncle             axis. Texture: Smooth, glabrous. Color: Close to 145B to             145C.         -   Reproductive organs.—Stamens: Quantity per flower: About 70.             Filament length: About 1.4 cm. Filament color: Close to             155C. Anther shape: Narrowly reniform. Anther length: About             2 mm. Anther color: Close to 150B. Pollen amount: Scarce.             Pollen color: Close to 158D. Pistils: Quantity per flower:             About six. Pistil length: About 1 cm. Stigma shape:             Club-shaped. Stigma color: Close to 145C. Style length:             About 9.5 mm. Style color: Close to 145C. Ovary color: Close             to 145B. Nectaries (transformed petals): Quantity per             flower: About 13. Length: About 9 mm. Diameter, apex: Close             to 2 mm. Diameter, base: Close to 1 mm. Shape: Flattened             triangular. Color: Close to N144A to N144B; towards the             base, close to N144C.         -   Seeds/fruits.—Seed and fruit development have not been             observed. -   Garden performance: Plants of the new Helleborus have been observed     to have good garden performance and to tolerate rain, wind and     temperatures ranging from about −10° C. to about 35° C. -   Pathogen/pest resistance: Plants of the new Helleborus have not been     shown to be resistant to pathogens and pests common to Helleborus. 

1. A new and distinct Helleborus plant named ‘COSEH 740’ as illustrated and described. 